Record Single-Mode, High-Power VCSELs by Inhibition of Spatial Hole Burning

In this paper, we present fixed-wavelength, vertical-cavity-surface-emitting lasers (VCSELs) based on InP with remarkable single-mode (SM) output powers. It is shown that a precise choice of the diameters of the ring geometry of the bottom GaInAs intracavity contact layer severely affects the guiding behavior of the fundamental and first-order modes inside the cavity. Experimental data, statistics, and theories will be discussed on how to overcome spatial hole burning and how to master thermal guiding and efficient current injection in order to extend SM output powers to beyond 8 mW at room temperature for VCSELs with 7 μm aperture. Coming along with side-mode suppression ratios exceeding 50 dB and continuous electrothermal wavelength tunings exceeding 8 nm, these laser devices define a new state of the art of electrically pumped InP-based short-cavity long-wavelength VCSELs at 1.55 μm emission.